Abstract The microstructural and mechanical properties of metal materials are affected by the cooling rate during the heat treatment. The temperature distribution and the corresponding cooling rate are determined by the heat transfer coefficient. To study the heat transfer coefficient of an advanced nickel-based superalloy during the end-quench process with air, the experimental and fluid-solid coupling numerical studies were conducted in this work. Furthermore, the apparent specific heat capacity associated with the cooling rate was applied to address the effect of phase transformation in the nickel-based superalloy. The results showed that the heat transfer coefficient at the quenched end reached over 400 W/(m2·K) at 800 K when the air flow was 2.7 m3/h because of the combination of a strong impinging jet and radiation heat transfer. Based on the simulation results, an empirical correlation among the heat transfer coefficient at the quenched end, the temperature and the flow rate of the air was proposed. The validity of the heat transfer coefficient model was verified by the temperature curves obtained in the experiment.

中文翻译：

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空气端淬试验中镍基高温合金传热系数的研究

摘要 金属材料的显微组织和力学性能受热处理过程中冷却速度的影响。温度分布和相应的冷却速度由传热系数决定。为了研究一种先进的镍基高温合金在空气端淬过程中的传热系数，在这项工作中进行了实验和流固耦合数值研究。此外，应用与冷却速率相关的表观比热容来解决镍基高温合金中相变的影响。结果表明，在气流为2.7 m3/h时，由于强冲击射流和辐射传热相结合，淬火端传热系数在800 K时达到400 W/(m2·K)以上。根据模拟结果，提出了淬火端传热系数、温度和空气流量之间的经验相关性。通过实验得到的温度曲线验证了传热系数模型的有效性。